A video posted to YouTube on Monday showed Dynamo appearing to float right outside the bus. His right arm was outstretched and his hand was touching the side of the bus. With his left hand, he was holding a cell phone.

The rest of his body appeared relaxed, although it was suspended in mid-air. He even kicked his legs back and forth a few times.

The video opened with Dynamo's narration as he walked down a street.

With that, a tight shot showed his feet leaving the ground next to the bus. When next he was seen, he seemed to be floating next the vehicle.

As he traveled the streets of London, pedestrians stared in amazement. Some chased the bus to record the spectacle on their cell phones, while others could be heard asking how he managed to pull it off.

Questions also swirled on social media.

Wrote Twitter user @supazeez: "Have u seen the pepsi max ad? Where a guy called dynamo was walking in the air holding a London bus wit one hand"

On Facebook, posters debated Dynamo's reflection, speculated about whether the arm touching the bus was fake, and questioned the bus route.

"Wait a minute there's no 543 in London !!???!" user Cormac Murphy wrote.

Pepsi's corporate media representatives did not return an after-hours email sent by ABCNews.com on Monday evening. However, in a news release from April 2012 that unveiled the campaign, the company said the initiative would "invite and inspire Pepsi fans to live each moment to the fullest through a breadth of global, pop-culture platforms, including relationships with music and entertainment brand evangelists, digital innovation, epic events and unique partnerships."